[opensuse] Enabling an external display on a laptop that shows disconnected.

I am trying to discover how to enable an external monitor that I plug
into my laptop. I am trying both 42.3 and 15. When I execute the xrandr
command by itself is shows HDMI-2 disconnected. My laptop screen
sometimes comes up as LVDS-1 unknown connection, where it certainly knew
the connection when I started the system (should be connected primary)

I have tried various xrandr commands advertised to work, the simplest
being sudo xrandr --auto. After many hours on google I always find the
xrandr --auto solution. The Opensuse system settings widget only shows
one display and no options to probe for others.

If I boot the system with the display attached it comes up correctly, so
the monitor and cabling are good.